Exhaust question I can't find an answer for..

B6/7 S4/RS4
#1

So I know everyone loves yet another exhaust thread but please bear with me. I’ve got my 05 S4 with stock exhaust that is falling apart, my flex joints are going and my mid-muffler support is rusted clean off. Everything is still stock on the exhaust except that I have gutted my pre-cats (so I have piggie pipes). I was in at the local exhaust shop today looking at options to fix/upgrade. I read through this thread:
http://audirevolution.net/forum/index.php?topic=3080.msg89612#msg89612 but couldn’t find a clear answer to my questions.

GOALS:

  1. Prepare car for the JHM tune to get the most I can from it (so I am assuming 2.5" is the minimum requirement here)
  2. Get some more of that wonderful V8 sound. I don’t need it obnoxiously loud (just had a baby, lots of road trips, etc) but I do want it to sound meaner than stock.

OPTIONS:

  1. Adapt from stock DPs up to 2.5", install X-pipe, and pipe to STOCK mufflers.
  2. Same as option 1 except delete the middle muffler/resonator as well.
  3. Buy a complete aftermarket catback (i.e. fast intentions, magnaflow, etc) and install

QUESTIONS:
I am most interested in hearing about option 1 or 2. I definitely want a 2.5" from the downpipes back but I have never heard about keeping the stock mufflers. So my questions are:

  1. Would keeping the stock mufflers totally cancel out any benefit of installing an x-pipe and 2.5"? How much potential gains do I lose by keeping the stock mufflers?
  2. Any pros/cons to removing or keeping the middle muffler?

Thanks!

#2

Any reason why you wouldn’t just go with a JHM exhaust? It sounds incredible and is the only one that has proven acceleration gains.

#3

Honestly, mainly just $. I’d rather not drop $1200+shipping+install costs on and brand new FI catback even though I would love to. I have 171,000 miles on the car I don’t want to dump in too much more money at this point. The main driver behind doing anything at all is that my current one is falling apart in the middle.

To fix it back to stock would be $400+ after parts, and the exhaust shop said they could do the x-pipe @ 2.5 back to the stock mufflers for pretty much same price. So I was wondering if that is any better than OEM. I’ve never seen anyone with 2.5"/x-pipe but back to stock mufflers.

And I do have the piggies, and I am still considering the tune, but I’m not going to tune if my exhaust isn’t capable of reaping any it’s benefits.

#4

The stock exhaust sounds terrible. The stock mufflers are for muffling to the biggest degree. If you push too much through them they will sound like crap.

I would look for a cheap used FI system. It has the X pipe and it has resonators the res really help keep the car tame on the inside of the cabon. If you look magnaflow systems are cheap.

#5

Thanks!! This is exactly the information I was looking to find. I’ll try to find a complete catback.

#6

Brian_216 is selling his used FI catback I believe.

#7

We made a deal yesterday actually! I had been talking to him about it but wanted to answer my own questions on the stock mufflers and whatnot before pulling the trigger on the more expensive catback. But this thread helped me decide I needed to go for it.

I also talked with Kevin at FI and he can sell me separate resonators if I want as well.

#8
  1. Find someone with newer piggies (newer than your old busted ones) and buy them for 200 bucks
  2. Find a used Fast Intentions catback and buy it for 700 bucks

Done

OR just find a newer stock exhaust form someone. Lots of guys save theirs when they upgrade… Then they get rid of it when they recognize that saving a 100 lbs 13 foot long chunk of metal is annoying.

There’s a guy on the Canadian az classifieds selling a full stock B7 system. I imagine he would take very modest money for it t9 get rid of it.

Since you have accomplished number 2. Just find a good set of stock downpipes and piggie them.

#9

Probably not a bad idea to replace the DPs, however I am not mentally prepared to tackle that job yet ;D. I have the TIP and no lift so removing and reinstalling the DPs now does not sound fun. I’m still recovering from this spring’s engine pull :smiley: I will probably wait until the flex joints actually start leaking to tackle that. At which point I’d look for some used trexturks or something.

Here is what happened, when I had them off with the engine out this spring, I took them into the shop to get new flex joints. But the exhaust shop did not want to replace the flex joints then because they said they could not weld the new ones on aligned correctly without them in the car. But of course, now they are back in the car they say there is no room to weld without removing them.

I can see their point both ways, I imagine some places might have a custom jig specific to this exhaust that makes things easier. Or are they just a lazy shop and didn’t want to take the time to set something up to be able to cut off and replace a new flex joint aligned properly with the downpipes out?

#10

I’m not sure if it’s my flex joints that are cracked but I was going to get a shop to take them off so I can make piggies but they said its leaking. So right now I’m trying to find a set of stock DP asap or aftermarket ones for a decent price but no luck. Is driving around like how I am with the leak/crack bad? What else could go wrong besides worst fuel economy and a raspy sound?

#11

Order up downpipes to go with this system. It’s set up for it already. My car had Texturk down pipes mated to a stock catback when I bought the car. The exhaust is a little bit shorter since it was made to run with downpipes. I had to make short adapters and cut the neck down off the Texturk pipes. Either way you will be doing a little nodding to make it work. Save a few bucks more and get downpipes. You will love the sound it makes. Also I know you were talking about resonators. Maybe with stock cats in place this might not be too loud? When I first installed I thought it was too loud. Then after a few days I loved it. I can’t wait to hear the RS4 with the new system. Good luck with it whatever direction you go. I’ll let you know as soon as FedEx picks up.
http://images.tapatalk-cdn.com/15/08/23/49ea3209d1f8dc7aa94c6be0afa6519a.jpg

#12

Brian what did you have? Texture catless and fast intentions non res? That’s way louder than an rs even catless.

My car is full jhm rs4 with high flow cats and it is nowhere near as loud as my B7 S4 was with catless 2.5 + resonated fast intentions. It’s not even as loud as piggies + fast intentions on the S4.

#13

Texturk catless and FI non res. It was loud. I loved it. My friend has a car lot and I am trading him for an 08 s line a4 for my wife. He didn’t want the exhaust thinking mom and dad will never buy that for their kid being that loud. I’m excited to get the a4. High pressure fuel pump wiped out the cam so I’ll have a little weekend project. But I added another B7 to the stable. But yea back on topic, it was loud. Very loud, but in a good way.